TRANSPORTATION
UNIT 5: USE OF THE DIGITAL
MULTIMETER
INTRODUCTION
Through the use of lecture, multimedia resources, demonstration, group activities, and hands-on
lab work the instructor will direct the student learning to safely and properly test the automotive electrical
system and components. Students will be instructed in diagnosis and service of electrical systems, subsystems, and components. Safety and environmental responsibility will be covered in detail. Safe, clean
procedures using recommended service tools will be included in instruction. Safety and environmental
responsibility will be covered in detail. Safe, clean procedures using recommended service tools and
equipment will be included in instruction. Procedures should include precautions for SRS (air bags), antitheft devices, and all of the vehicle's computer systems. Separate instruction should cover High Voltage
Systems.
Course: 47.571 Foundations of Transportation & Logistics
Unit Development Template Annotation
In this unit students will identify the importance of safe tool use. Students will review basic electrical
principles. Emphasize importance of correct electrical testing procedures in the lab exercise. The use of
multimeter (DMM) used as a voltmeter, amp meter and ohm meter, electrical test equipment, and service
procedures.
Grade(s)

9-Ninth

10-Tenth

11-Eleventh
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Unit FTL 5 • Page 1

12-Twelfth
Time:
6
Author

Sonny Reeves sreeves.hutchingscc@bibb.k12.ga.us www.autoteacher.net
Notes to the Teacher

Safety cannot be reinforced enough. An OSHA approved safety shower and eye wash should be
accessible by all persons engaged in this lesson. Shop safety issues are to be reviewed and
stressed in this lesson. The service information for the vehicle systems being used in the
demonstrations and practice should be available. Disconnect or remove air bags and/or use
vehicles without the systems. For student practice a module can be used for most of the testing.
Students with disabilities: For students with disabilities, each instructor should refer to the student's IEP
to be sure that the accommodations specified in the IEP are being provided within the classroom setting.
Instructors should also familiarize themselves with the provisions of Behavior Intervention Plans that may
be part of a student's IEP. Frequent consultation with a student's special education instructor will be
beneficial in providing appropriate differentiation within any given instructional activity or requirement.
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STANDARDS
GPS Focus Standards:
ACT-FTL-4: Describe and explain the properties of electricity.
ACT-FTL-5: Demonstrates knowledge of related physical science principles.
GPS Academic Standards:
ELA10W3 The student uses research and technology to support writing.
SPS5. Students will compare and contrast the phases of matter as they relate to atomic and molecular
motion.
NATEF 2008 Standards:
1. VI A 5.Diagnose electrical/electronic integrity of series, parallel and series-parallel circuits using
principles of electricity (Ohm’s Law).
2. VI A 7. Demonstrate the proper use of a digital multimeter (DMM) during diagnosis of electrical
circuit problems including source voltage and voltage drop, current flow and resistance.
3. VI A 8, Check electrical circuits with a test light; determine necessary action.
4. VI A 13. Inspect and test fusible links, circuit breakers, and fuses; determine necessary action.
NATEF Academic Standards:
LA283, The technician uses computerized and other databases to obtain system information.
LA285, The technician can comprehend and apply information in operator's manuals to operate and
maintain automotive tools and equipment.
MA176, The technician interprets symbols to determine compliance with the manufacturer's
specifications.
MA001, The technician can use Ohm’s Law to determine circuit parameters that are out of tolerance.
SC177, The technician can demonstrate an understanding of and explain the properties of electricity that
impact the lighting, engine management, and other electrical systems in the vehicle.
SC198, The technician can demonstrate an understanding of the correct procedure to measure the
electrical parameters of voltage, current, resistance, or power.
UNDERSTANDING AND GOALS
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Unit Understandings, Themes, and Concepts:

Students will understand that knowledge of the basic laws of electricity is the key to the
technology of the future.
Primary Learning Goals:
EQ: What are the properties of electricity and how does a technician use them to service the
vehicles electrical system? How do volts, amps and ohms relate to each other?
EQ: What are the physical science properties related to automotive service and repair?
What are the laws of electrical force? How can I use electrical laws to diagnose electrical
problems on vehicles?
What are the safety concerns for the technician in electrical testing?
What hand tools are special to electrical testing?
Why are clean, orderly work habits important?
What are the Health and Safety regulations for working with electrical test equipment and circuits?
What are correct voltage levels for the circuit being tested?
What are amperage levels of the circuits being tested?
What are the types of the circuits used in the different electrical components?
What are the ways of testing resistance in the circuit?
Define voltage, resistance, and current flow.
What electrical laws must the electrical technician know?
BALANCED ASSESSMENT
Assessment Method/Type:
#
Constructed Response
Peer Assessment
Combined Methods
Selected Response
Informal Checks
Self Assessment
Assessment Title: Inspecting and testing a battery.
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Description/Directions: Download assessment from
http://www.cdxetextbook.com/PDF/ac/testbat_AC.pdf
Have students follow worksheet for practice and teacher assessment of the practice .
Attachment – Supplemental Resource Title: Work Sheet, Testing a Battery Worksheet, Battery Test
Web Resources:
Web resources are embedded and annotated in sequence steps.
Additional web resources can be found at
https://www.autoteacher.net
UNIT PERFORMANCE TASK(S)
Performance Task Title: Battery Core Skills 1
Description/Directions: When students complete job sheet, and/or follow activity guide and have
practiced the tasks the instructor may use the attached performance test for final assessment and to
prove their level of mastery for unit. The performance test may be used by students during practice for
peer assessment before instructor sign off. The completed rubric is placed in student portfolio for future
reference. The performance test may be modified to suit individual teacher/student needs.
Rubric for Performance Task:
Download copy from
URL Elect_PT_BatteryCore_Skills1.doc
Copy of document;
Name _____________________ Date_________________ Core Skills Battery 1
NATEF Task Area: VI. ELECTRICAL/ELECTRONIC SYSTEMS task area VI
Objective; Student will be able to: safely test, diagnose, service, repair and make necessary
corrections to electrical circuits, components using correct procedures, proper tools, and test equipment
Practice only after instructor demonstration! Ask permission first!
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Reference: http://cdxetextbook.com/
Performance Indicators
Student Check
Instructor Check
Poor
Poor Average
Excellent
Average Excellent
1. VI B 1, Perform battery state-of-charge test; determine
necessary action.
2. VI B 2, Perform battery capacity test (or conductance
test); confirm proper battery capacity for vehicle
application; determine necessary action.
3. VI B 3, Maintain or restore electronic memory
functions.
4. VI B 4, Inspect and clean battery, battery cables,
connectors, clamps and hold-downs and/or replace
battery.
5. VI B 5, Perform battery charge.
6. VI B 7, Start a vehicle using jumper cables or an
auxiliary power supply.
Safety rules
Use of reference materials
Tool use
Proper procedure
Diagnosis and answers to electrical questions
Student Signature ________________________ Student Check Name_________________
Instructor Signature________________________
All repairs and service procedures are to be done in SAFE, Proper manner, All SAFETY Rules Apply!
Neat, Clean, and you must wear Safety Glasses at all times. Violation of safety rules will cause testing to
terminate with result of negative grade for this performance test.
Scoring:
4 Mastery- Student successfully applied knowledge or performance to all tasks independently.
3 Proficient - Student met knowledge or performance tasks without assistance on most tasks.
2 Basic - Student met knowledge or performance tasks with or without assistance on some tasks.
1 Unacceptable - Student unable to meet knowledge or performance criteria and /or required much
assistance.
SEQUENCE OF INSTRUCTION AND LEARNING
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Materials and Equipment
For Student use:
1. Several digital multimeters (DMM), Fluke 87 or equivalent recommended with high and low volts
range anle to test current flow (amperage test) and ohms/resistance test.
2. Extra lead sets with fuses.
3. Several non-powered test lights.
4. Electrical components and/or electrical test modules set up
5. Several vehicles with working and non-working electrical systems
6. Wiring harness examples (scrap harnesses)
8. Basic hand tools
9. Special service tools for vehicles being used
10. Reference materials such as factory service manuals, electronic service information, and
specifications from electrical component suppliers
11. Handouts of wiring diagrams examples
12. Safety glasses and protective clothing and cleaning supplies
Sequence of Instruction and Learning:
Step: 1
Introduce students to the multimeter (DMM) and test light with voltage testing. Begin testing with
review of safety in the use of electrical testing. Warn students of the dangers associated with typical
lead-acid batteries. Refer to previous lesson on shop safety. Use a live 12-volt automotive battery or
vehicle system for this demonstration. Use a electrical trainer module for demonstration. A module
that allows smooth transition to live vehicle is recommended. Demonstrate what occurs when a direct
short is put into a circuit in a controlled, safe manner. Use a covered or remote battery for students to
experience safety precautions. You may want to use a set of dry cell 6-volt batteries or power supply
to prevent explosions of hydrogen gas. Be sure to stress the dangers of working on live circuits, wet
cell batteries, and electrical components.
Web Resources for Step 1
Title: Testing with a Multimeter
URL: http://www.fluke.com/application_notes/automotive/beatbook.asp?AGID=1&SID=103
Annotation: The Fluke Web site is excellent for meter use training and electrical testing review.
Students can quickly access the information they need for automotive electrical testing.
Title: Electrical Principles
URL: http://www.autoshop101.com/
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Annotation: Interactive web site with basic electronics and testing procedures in several formats
Title: Electrical & Electronics
URL: http://www.cdxetextbook.com/electrical/electrical.html
Annotation: Interactive web site with videos, resources and graphics for electrical training.
Step: 2
Duration: 40 min
Review electrical principles. Stress the three measurements of voltage, ohms and amperage.
Describe how an inductive lead works. Have students access electrical course on resource sites or
show on interactive white board with projector. Show theory and operation of electrical circuits.
Discuss operation and design. Have students research Fluke Web site for information on digital
multimeters (DMM) and testing. Demonstrate meter use to students. Have examples of electrical
components to pass around in the class to emphasize key points of electrical principles.
Web Resources for Step 2
Title: Basic Electrical Training
URL: http://gworobec.users.50megs.com/site1010.html
Annotation: Mr. Worobec's site is a great resource for student learning online. Students can select
electrical theory training from a menu that covers basic electrical to computer system operation.
Step: 3.
Place an electrical circuit set-up on a workbench. Demonstrate use of multimeter (DMM). Use an
example of a wiring harness or fuse panel to show how resistance and continuity relate in testing.
Stress importance of proper procedure in testing circuits for ohms and amperage. Do not allow
students to damage meters! Make sure they are fused. Add fuse to lead if needed. If you are using a
wet cell battery consider placing it in a protective box or remote location to prevent explosion.
Demonstrate use of voltmeter in low and high voltage mode. Demonstrate use of low/high ohms.
Demonstrate use of amp probe and low amp testing. Demonstrate use of test light. Show students
the limitations of the test light vs the DMM. Allow students to practice use of meter and measurement
tools. Reinforce math skills with use of Ohm’s law.
Step: 4
Demonstrate the use of multimeter (DMM) on live vehicle that is in good condition. Show students
examples of meter use to test battery voltage throughout circuit. Demonstrate resistance in a circuit.
Prepare a “problem” circuit on the vehicle and demonstrate finding the problem with the meter.
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Demonstrate measuring starting and charging voltage levels. Discuss service problems and solutions
of the different problems technicians may encounter.
Step 5
Demonstrate use of low amp probe on live vehicle to show key off drain. Explain this is what happens
when you leave the lights on! Demonstrate use of 10 amp current flow through meter. Demonstrate
amp probe to measure higher current flow. Measure starter current flow on vehicle in good condition.
Allow students to practice the procedures with instructor observation.
Title: Electrical & Electronics
URL:
Work Sheet DMM Test and activity guide,
http://www.cdxetextbook.com/PDF/ac/continuity_AC.pdf
Annotation: Work sheet and activity guide for student assessment and student practice
Step: 6
Set up several vehicles and /or modules with working electrical systems. Divide students into teams.
Have students use work sheet to practice for performance test. Observe and monitor student
progress. Facilitate the measurement and comparison of good and defective parts. Set up a few
“bugged” components to challenge students. Encourage all students to practice the job skills for the
performance test. Allow students to refer to web sites and videos for review.
Web Resources for Step 6
Title: Electrical Theory and Basic Electrical Systems
URL: http://gworobec.users.50megs.com/eleccirc.html
Annotation: Mr. Worbec's site makes the complex simple for students.
Title: Fluke Meter Automotive Testing Site
URL: http://www.fluke.com/application_notes/automotive/circuit.asp?AGID=1&SID=103#volt
Annotation: Menu of automotive electrical testing procedures using Fluke or similar multimeter
(DMM) to measure electrical values.
Title: Performance Test
Step: 7
Duration: 80 min
Allow students to practice and complete worksheets and performance tests. Use performance test
and work sheet for assessment of student learning.
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